<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>样式</title>

    <style>
        div{
           /*边框 */
           border: 1px solid green;
            /*宽度*/
            width: 60%;
            /*高度*/
            height: 600px;
            margin: auto;
        }

    </style>
</head>
<body>




<div>你别管我 你看好自己</div>
</body>
</html>